Currently, digital cameras which record images with image-capturing elements become popular, in place of conventional film cameras which capture images with films. In most cases, the digital camera obtains an image signal having three colors, RGB, by photoelectrically converting light transmitting through a three color (RGB) filter with the image-capturing element. The digital camera performs conversions such as Bayer interpolation, white balance conversion, matrix conversion, and gamma conversion on the obtained image signal to convert the signal into image data optimized for viewing on a display. The converted image data is recorded in a file format, such as JPEG.
In the case of photography with a conventional film, the film is loaded in a camera to perform photography and then develop the film. Thereafter, image reproduction is performed by printing or by projection with a projector. Although digital cameras are popular in recent years, an appearance resulting from the image reproduction with the conventional film may sometimes be desired. In order to meet this need, digital cameras or application softwares may be provided with a mode intended for film tone reproduction. In order to perform such a reproduction, an image processing device has been proposed which is able to perform a conversion on an image photographed by a digital camera to obtain a film tone image, for example (see PTL1).
In order to obtain a film tone image, the image processing device sequentially performs white balance processing, color conversion matrix processing, and gradation conversion processing on the image which has been photographed by a digital camera and has been subjected to Bayer interpolation processing. In the image processing device, the white balance processing, the color conversion matrix processing, and the gradation conversion processing are performed with parameters of respective processing optimized to achieve the film tone reproduction.